PAV3 high pressure chamber and VDO touch degassing furnace allow you to simulate bitumen aging for subsequent laboratory tests
In 2020, a large-scale upgrade of equipment is taking place in the stationary laboratories of the FAU "ROSDORNIA" within the framework of the national project "Safe and High-quality Roads". The new equipment will be used in the framework of quality monitoring (audit) for testing road construction materials for compliance with the requirements of existing regulatory and technical documents. We talk about new progressive installations and devices in detail.
Bitumen binders are subject to aging, that is, their properties change over time under the influence of various factors. There are two types of aging of bitumen binders – during the production of asphalt concrete mixture and during the operation of asphalt concrete.
PAV3 high pressure chamber is designed to simulate the aging of bitumen binder during the operation of asphalt concrete in accordance with GOST R 58400.5-2019 "Public automobile roads. Materials binding petroleum bitumen. The method of aging under the influence of pressure and temperature (PAV)". This technique allows for several hours to simulate a change in the properties of bitumen binder, corresponding to 5-10 years of asphalt concrete operation.
The essence of the method consists in exposing the binder samples placed in a sealed test chamber to high pressure (more than 20 atmospheres) and high temperature (up to 110 0C) for 20 hours. After completion of the tests, a vacuum degassing furnace (VDO) is used to remove air bubbles from the samples of the tested binder, in a sealed chamber of which a vacuum and a temperature of 170 ℃ are created.
The PAV3 installation consists of a vertical high-pressure chamber for the placement of the test samples, into which pressure and temperature sensors are integrated, and the heating elements are controlled by a digital controller. The device is controlled via a digital controller interface with a touch screen.
The main element of the VDO degassing furnace is stainless steel chamber, accommodating up to 4 containers with bitumen binder. The required discharge is maintained automatically, the time, temperature, and the current stage of the degassing process are displayed.
According to the results of further tests of artificially aged samples, the lower limit of the temperature range of the bitumen binder operation is determined. The tests can be carried out using a beam bending rheometer in accordance with GOST R 58400.8, using a dynamic shear rheometer in accordance with GOST R 58400.9 or using an Asphalt Binder Cracking Device (ABCD) installation in accordance with GOST R 58400.11.